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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>All,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Though this question is not specific to GDAL, OGR or
FWTools, I believe some of the most knowledgeable people of the subject are on
this mailing list and hope you will allow me to ask.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>At my company, there is an ongoing debate as to the best
coordinate system to store cooperate spatial data in. The debate is
mainly between the Geoscience department and the GIS department. The vast
majority of the data the Geo’s use comes from public sources that are in
geographic lat/lon in NAD27. This data is then reprojected for mapping
and display in various coordinate systems, state plane and UTM (zones 12
– 18, but mostly in 13, 14 and 15). The GIS guys supply many layers
to the Geo’s for display. They are currently upgrading from ArcSDE
9.1 to 9.2, and in the process are converting all their coordinates for storage
in UTM zone 14. GIS made the comment that this is a much more accurate
way to store the data, that geographic coordinates are less precise, though,
their main reason for storing the data in a projected system is to avoid having
to do any coordinate conversion on the fly when displaying the data on
corporate web maps. The layers supplied to the Geo’s will need to
be reprojected if their current map projections are not UTM Zone 14.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>The question: is it wise to store coordinates that cover
such a wide area in a single projected coordinate system, or would it be better
to store them in some geographic coordinate system, e.g., NAD83 or WGS84?
And if this not the best way (UTM14), why? What are the pitfalls?
Is it really more accurate, or precise to store data in a Cartesian coordinates
and suffer the conversion to a different projection as needed?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Thanks,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>David<o:p></o:p></span></font></p>
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